Finding the Third Proportional to 1,287.28 and 2,768.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.28 : 2,768.63 = 2,768.63 : x
2. Step 2: Convert to fraction form
   1,287.28/2,768.63 = 2,768.63/x
3. Step 3: Cross multiply
   1,287.28x = 2,768.63 × 2,768.63
4. Step 4: Simplify right side
   1,287.28x = 7,665,284.39
5. Step 5: Solve for x
   x = 7,665,284.39/1,287.28
6. Step 6: Final answer
   x = 5,954.63